This invention relates generally to an improved photo flash lamp and more particularly to an improved photo flash lamp which is provided not only with a strobe flash lamp but also is provided with constantly illuminated examination lamps to enable shadowless illumination of the subject prior to film exposure.
A recurrent problem in photography, and especially medical photography, is the inability to obtain sufficient illumination of the subject matter to be photographed to enable the subject matter to be brought into sharp focus prior to film exposure. In medical photography, the need to obtain a sharp focus of the subject matter is particularly important, especially where the photographic images are to serve as the basis for diagnostic screening, such as when practicing the diagnostic screening method for cervical cancer described and claimed in U.S. Pat. Nos. 4,300,570 issued to A. Stafl, hereinafter referred to as the Stafl patent. Unless the photographs obtained are clear and sharp, the usefulness of the photographs or slides for diagnostic screening purposes and particularly for the diagnostic screening of cervical cancer in accordance with the method taught by the Stafl patent, will be minimal.
Often, ambient room light is insufficient to provide proper illumination of the subject matter, thereby preventing sharp focusing of the subject matter in the camera lens. This is particularly true where the subject matter to be photographed is in a body cavity, as when practicing the method of diagnosing cervical cancer as taught by the Stafl patent. In the photographic apparatus shown in the Stafl patent, a fiber optic light source was mounted to the outer periphery of the case of the ring strobe to illuminate the cervix prior to film exposure so that the camera lens may be properly focused to obtain a sharp clear image of the cervix. While the use of a single fiber optic light source does illuminate the cervix, shadows and uneven illumination can still result and may prevent sharp focusing. Moreover, mounting the fiber optic light outside of the ring strobe of the camera, increases the likelihood that the fiber optic light source may be damaged during transport.
Another recurrent problem in photography and particularly medical photography is knowing when the flash lamp used to illuminate the subject matter during film exposure has been sufficiently recharged to permit subsequent film exposure. Most present photographic flash lamps utilize a Xenon flash tube which is ionized when a precharged capacitor is discharged across the Xenon flash tube in synchronization with the actuation of the camera shutter by the photographer to provide a high intensity burst of illumination during film exposure. Most commercially available flash lamps includes some type of indicator for alerting the photographer as to when the capacitor within the flash lamp has been sufficiently recharged to re-ionize the Xenon flash lamp tube to provide the illumination necessary for subsequent film exposure. However, such indicators are often unreliable and moreover, photographers sometimes inadvertently ignore the flash lamp indicator. Believing the flash lamp has been recharged, the photographer subsequently exposes the film, only to later learn that the flash lamp did not trigger because the photographer did not allow sufficient time to elapse for the flash lamp capacitor to be recharged. Thus, a reliable indicator for accurately indicating when the flash lamp has been recharged would be extremely useful.
Presently commercially available cameras are now provided with sophisticated electronic circuitry within the camera for alerting the photographer if sufficient light is available to obtain the proper film exposure. Thus, if the flash lamp could signal the camera that the flash lamp capacitor has been sufficiently recharged to trigger the Xenon flash tube, then the photographer would be alerted not to inadvertently expose the film until the flash lamp was ready.